Manufacturers of asphalt shingles have, for many years, endeavored to produce shingles that resemble natural materials in appearance. Typical materials that manufacturers have sought to have asphalt shingles resemble are natural slate and cedar shakes. Techniques that manufacturers have employed have included applying an overlay to the shingle, or making a multiple-layered or laminated shingle.
In U.S. Pat. No. 4,352,837 to Kopenhaver, an overlay is taught, whereby, after a single layer of shingle is made, comprised of a mat, asphalt, and granules on an upper surface, the single layer thus made receives an overlay in the form of an additional partial coating of asphalt, which in turn, receives additional granules thereon, creating localized areas of additional thickness on the shingle, with such areas of additional thickness having the desired ornamentation.
In U.S. Pat. No. 5,181,361, to Hannah, et al, there is taught a laminated shingle, in which the shingle is comprised of a base layer and a secondary layer, and with a partial top layer, with each of the layers being comprised of an asphaltic web with granules applied to the top of the web, to yield a shingle with some portions being of two-layer thickness and other portions being of three-layer thickness.
Whether the shingle is of the overlay type or of the laminated type, various ornamental effects can be achieved by the use of variously colored granules.
Whether the thicker-appearing shingles are made by overlay techniques or by laminating layers together, there is, in each case, an additional expense associated with doing so, both in the use of additional materials, and in additional manufacturing steps.
The present invention is directed to creating the appearance of a thicker shingle, by employing a combination of slots and transverse or vertical visually distinct shading areas on each of the slots, relative to areas of different shading therebetween. The effect thereby makes the tabs appear to be thicker than they actually are. The visually distinct shading of the vertical areas where the slots exist is comprised of granules other than the granules that are used in the intermediate areas.
Accordingly, it is an object of this invention to provide a novel multi-tab shingle, having a thicker appearance for the tabs than the actual thickness of the shingle.
It is another object of this invention to accomplish the above object, wherein the shingle presents vertical or transverse shadow lines, substantially darker than adjacent areas of the tabs.
It is another object of this invention to provide a novel method of making such shingles.
It is a further object of this invention to provide novel apparatus for making said shingles.
It is another object of this invention to provide a novel method of and apparatus for synchronizing the cutting of slots between tabs such that the slots are located at the centers of the vertical or transverse shadow lines of the shingles.
It is a further object of this invention to provide a means for synchronizing the placement of the slots on a substantially continuous basis, by periodically sensing the placement of shadow lines on the shingle, and then correcting the location of cutting accordingly.
Other objects and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the following brief descriptions of the drawing figures, detailed descriptions of the preferred embodiment and the appended claims.